Heretofore there have been many different types of industrial cleaning machines or apparatus provided. Some of these structures are shown in my prior U.S. Pat. Nos. 2,619,100; 2,564,443 and 2,437,968. Industrial tank cleaners of the types shown in these patents have been made and sold commercially for a number of years. However, in these industrial cleaners, there is an outboard motor type of a drive means and mixing propeller provided to stir the hot cleaning materials usually used therein. Heretofore, tanks of the type referred to have had relatively good service lives and have done excellent cleaning actions, but there is the problem of sealing the housing and drive means for the drive propeller so that the hot cleaning liquid or other material in the tank does not work its way into the propeller drive assembly. And service has been required for these seals in prior types of these cleaners.
Accordingly, it is the general object of the present invention to provide a new and improved propeller and drive means assembly for industrial cleaning machines and particularly to propeller and drive means that can be readily assembled onto or be moved from engagement with the remainder of the cleaning tank.
Another object of the invention is to provide a propeller and drive unit for industrial cleaning apparatus and wherein improved seal means are present between the rotary output shaft of the drive unit and the stationary housing means enclosing lubricant for the propeller and drive unit therein.
Other objects of the invention are to provide a seal in a drive unit for use in submerged liquid conditions wherein the seal includes first and second hardened metal seal rings having flat sides thereon and resiliently pressed into engagement for sealing action between a rotary seal ring and a stationary seal ring; to provide an additional pair of seal rings wherein they have an O-ring positioned therebetween and tapered faces on the rings engage the O-ring and force it to compress and seal against a sleeve unit on which it is positioned; another object of the invention is to provide carbide seal rings for sealing a driven output shaft in an industrial cleaning machine and wherein an annular recess is formed in a flat face of one seal ring intermediate the radially inner and outer edges thereof and wherein such apertured seal face engages a flat surface of an adjacent seal ring operatively associated therewith; and to form an improved seal assembly for a drive shaft.
The foregoing and other objects and advantages of the invention will be made more apparent as the specification proceeds.